Posted by **al** on Wednesday, January 12, 2011 at 11:34pm.

solve with substitution

5x - y=-1

15x=2y

- math -
**Haley**, Wednesday, January 12, 2011 at 11:42pm
solve the first equation for y.

5x-y=-1 subtract 5x from both sides

-y=-1-5x divide by -1

y=1+5x

now, plug this answer in for y in the second equation.

15x=2y

15x=2(1+5x)

15x=2+10x

5x=2

x=.4

plug this(x=.4) into the equation for y.

y=1+5x

y=1+5(.4)

y=1+2

y=2

therefore, x=.4 and y=2 or (.4, 2)

- math -
**al**, Thursday, January 13, 2011 at 12:37am
actually that does not work out, plug x and y into original equation...

- math -
**al**, Thursday, January 13, 2011 at 12:39am
actually that does not work out, plug x and y into original equation...

y=1+2

y=3

then it works out

## Answer This Question

## Related Questions

- Math - Solve by Substitution method. 15x-20y=-7 15y=4+5x
- math - Solve by elimination 5x+y=2 3x+y=1 This is what I got : 3(5x+y=2) -5(3x+y...
- Algebra - I need help trying to put the correct vocabulary words when solving ...
- Algebra help! - 1.) Solve the system by triangularizing the augmented matrix and...
- algebra - i need help with these problems (either a solution or how to plug them...
- Geometry :( - this maths problem is wrecking my head.... 1.find the points of ...
- Math - 17) solve this linear system using the method of substitution. 2y-x=-10 y...
- Algebra - I need help trying to put the correct vocabulary words when solving ...
- math - solve each system of equations by substitution. y=3x-9 please help ...
- Substitution Method-Plz help - Use the Substitution method to solve the system ...

More Related Questions